Joining wooden pieces and cement therefor



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QATFNG 0R PLASTIC 8 i Patented Apr. 8, 1924.

Cross Reference 1,489,991 PATENT OFFICE.

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To all whom it may concern:

' lie it known that I, Hnmzr V. DUNKAM, a citizen of the United States, residing at Mount Vernon, in the county of Westchester and State of New York, have invented certain new and useful Im rovements in J oin-' 'ing Wooden Pieces and ement Therefor, of which the following is a specification.

The present invention relates to joining wood or wooden articles, such as wooden veneers and the like, by means of a novel adhesive. v

Various adhesives have heretofore been em loyed in gluing wood such as veneers, an most of the ad esives so employed have been open to certain objections. Adhesives containing sodium silicate have been roosed, but "sBfifiFknow most of t ese ave not given very satisfactory results when used in joining wooden veneers, the greatest objection being that the wooden veneers do not remain firml joined together, but after a time they tend to separate, es ecially where they are subjected to alternating excessive wetting and drying. When the sodium silicate adhesives have heretofore been employed, in most cases they eventually reduce themselves to coarse or fine powders which do not. have any good adhesive properties.

I have found after many trials, that so 1 dium silicate solution or ordinary waterlass can form the basis of a very sat 1sIac-' ory adhesive for wood, including veneers,

I if the same is first mixed with 9. ve fine The asbestos WHIOE has fibro' s asbestos. given very satisfactory results is almost the condition of a powder, but upon examination it will be seen to consist essentially of very fine fibers. An amount of this asbestos egual to from 2 to 7 percent, has been ound to be especially suitable, when mixed with ordinary grades of-water-glass. The different grades of water-glass can be used, and I have secured very good results with what is known commercially as Q de this containing 8.9 per cent of a,

an per cent of SiO,, the remainder bein 1' water. The 13- de can alsobe so This contains 32.9 per cent of Si the remainder bemg water. However, I do not restrict myself to either one of these two grades of water-glass. It is furthermore advisable, although not essentially necessary, to add to the mixture something which. will give increased tackilasses liesive can also 53 added if desired.

Application filed April a; 192 Serial Io. 460,088 A A B- ness to libel product. Als exam les of such mate'ria Y mention ucose extrin, mo-

rosin size. .Any otli'er suitablei d As example of mixed adhesives, I will state that a mixture of 7% parts of dextrin 1/ 10 parts of waterand 15 artsof molasses Q can be addeml) parts 0 waterlass containingJ 5*per cent of asbestos of %lie charactera ove specified. mexample consists in addin t 250 partsof water-glass of the U- a e above specified, 8 parts" "of fine gs fiest os, and 20 parts of rosin size. The rosin slzize i s prefers. ly first mpIllstened with 7 a sma quantity of wate or classes say 20 parts of molasses.

250 parts of waterlass N- ade, added t to 10 parts of tliorou 'hly in; m corporated, and there are then added 20, parts of molasses. Another example-10 grams ofd; latine, previously softened up with wa er, re dded instead of the molasses. Y

Another example which has given good results is-500 parts of the silicate ,solution, 10 parts of asbestos these mg thorou hly incorporated. and 5d the mixture was a dad a mixture of 15' parts of ta '5 cold water soluble) mixed w1t wa er I5 most of the examples above specified, I. have used small amounts of asbestos, somethinglesgthan 2 per cent of asbestos can, under some conditions; behmpldyed, even as low as 1 per cent being in some cases, suitable. In other cases 4 or 5 per cent, or up to about 7 er cent of the asbestos can be. employed. uch large quantities of asbestos ten to 've extremely thick mixtures.

, The a hesive as above stated is especially for the uniting of wood such as wood veneers and the like. The adhesive is a thick viscous mass, rather thicker than ordi'nary mos, approaching a semi-.jelly-like and colloidal mass, when containin about 2 per cent'ofthe asbestbs. This a esive is applied in the ordinary way, b a brush, or preferably by a roller, to one thickness of the wood veneer, and another thickness is er cent of Na,O and laid thereupon with the grain running approximately perpendicular-to the gram of the first piece and then high pressure is applied to squeeze the two sheets together as tightly as possible. It is preferable to use a hydraulic or some other press which will give very strongpressure upon the wood.

, Examiner The wooden articles are then allowed to dry and are ready for use for any desired purpose. as many thickneses of wood can be employed as are necessary to produce the desired product and veneer can also be attached to thick pieces of wood such as v boards, table tops and the like, either one-or more thicknesses of veneer being so applied.

I make no claim in this application to 'the adhesive, except where the same is used in connection with a wooden article.

While in most of the examples I have specified other materials to be added to the mixture of silicate solution and asbestos, these two can be used without any other additions, if desired. The mixture of these two is a non-settling, substantially colloidal mixture, very much more viscous than the water-glass used. Obviously, potash wajgr; glass can besubstituted for so um com- I claim: 1. A process of joining wooden pieces It is, of course, to be understood that which comprises app] in between the same a layer of a) viscous duid comprising as its essential constituents, a dissolved silicate and a very fine fibrous asbestos, and then pressing the wooden pieces together.

2. A cement particularly suitable for joining wooden pieces, the same com rising an alkali silicate solution, and fine brous asbestos, the said ingredients being completely mixed to produce a substantially non-settling, thick viscous solution.

3. A cement particularly adapted for joining wooden pieces, the same comprising an alkali silicate solution and fine fibrous asbestos, and another adhesive capable of increasing the tackiness, such ingredients being completely mixed together, forming a thick liquid mass of high viscoslt 4. A cement as covered in c aim 2 in 4 HENRY V. DUNHAM. 

